The invention relates to a medical handpiece having a rod-shaped grip part having a holding device disposed in a forward end region with a lateral insertion opening for a working tool defining an obtuse angle between the respective axes of the insertion opening and the gripping part of the handpiece.
Such a handpiece serves for the treatment or material removing working of the human or animal body with a movable, in particular rotatable tool, and is required to fulfil inter alia two main requirements. On the one hand it should have an ergonomically favourable constructional form, so that the operating person is able to hold the handpiece with the operating hand with an effort in terms of manipulation and use of force which is as little as possible, and further is able to move the handpiece to and at the treatment site in order to carry out the treatment or the material removing working. Thereby, in many cases of working, precision working is to be carried out which requires a precise movement of the handpiece, e.g. when working up a cavity or when working on a tooth stump of a tooth for a dental crown. One condition for this is that the operating person can ergonomically favourably grip the handpiece. On the other hand, the handpiece should be of such a constructional form that it can also been used in a readily manipulable manner when the working site is located in a body aperture, such as is e.g. the case with a mouth. Here it is to be striven for that the handpiece should also be advantageously employable even with restricted space and visibility conditions.
For fulfilling the first requirement, a so-called angled handpiece has been developed which has an acutely angled neck part which at its free end is thickened in a head-like manner and has a holding device with a lateral insertion opening for a tool. Due to the lateral acute angling, the grip part has a bend, whereby the insertion opening and the tool inserted therein are located on that side of the grip part toward which the bend faces. Such an angled tool be gripped manually ergonomically favourably and can be guided when working, whereby e.g. pressure is exercised on the handpiece with a finger of the operating hand in its concave bend region. By these means, when working, the handpiece is located in a stable condition which makes possible a movement of the handpiece under the applied pressure in a readily manipulable manner. This known angled shape of the handpiece has also proved to be advantageous in the case of restricted space conditions at the site of treatment, in particular in the region of a mouth. Thereby, the angled handpiece is introduced into the body aperture through the body aperture opening in a per se known and conventional grip position of the operating hand, whereby also here the position of the angled handpiece which is stable in consideration of the pressing forces on the tool advantageously comes about of itself.
A dental medical handpiece of the kind indicated in the introduction, in the shape of an angled handpiece, is described in WO 96/41583. With this known angled handpiece the middle axis of a holding device integrated into the angled holder limb includes an obtuse angle of 130 to 107xc2x0 with the middle axis of the angled holder limb. This constructional form is intended to be particularly adapted with regard to the anatomical relationships of human jaws, so that it is intended to be possible, in the restricted space available between the upper and lower jaw, to work on the teeth also in the rearward region (molars) in a favourable position.
There has furthermore become known a turbine handpiece in the form of an angled handpiece, with which the middle axis of the holding device includes an obtuse of 95xc2x0 with the section of the middle axis of the angled neck part extending rearwardly from the intersection point of this middle axis.
The object of the invention is to so configure a medical or dental-medical handpiece of the kind indicated in the introduction, that its suitability for use also in small spaces is improved. In particular, its shaping is to be improved in consideration of the anatomical form of the human jaw or the human open mouth.
According to the invention, a forward grip section of the grip part is curved toward the side of the end piece away from the insertion opening at an obtuse angle greater than 95xc2x0and small than 103xc2x0.
With the configuration in accordance with the invention, a forward grip section of the grip part is curved towards the side of the handpiece away from the insertion opening, and the middle axis of the insertion opening of the holding device includes with the middle axis of the handpiece an angle which is smaller than 103xc2x0 and greater than 95xc2x0, advantageously about 100xc2x0. In tests it has proved that just this angular range, taking into account an imaginary line or curve in space, in which the tooth tips of an average lower jaw of the human jaws lie, is particularly well adapted and thus favourable. By these means it is possible to reach not only the teeth in the forward region of the lower jaw but also in the rearward region in spatially favourable manner, so that the working surface on the respective tooth can be worked in a specific position of the handpiece without the handpiece coming into collision with the boundaries of the mouth or with the teeth of the lower or upper jaw, and without the lower jaw having to be opened extremely wide. By these means a significant improvement is attained, which substantially facilitates the working, because the patient can be treated with an ergonomically favourable manipulation by the operating person even in the case of a smaller mouth opening. Thereby, the operating person can give more attention to the quality of the working or treatment. The configuration in accordance with the invention thus leads to an improvement both for the patients and also for the operating person or the dentist.
The curvature is preferably adapted to the anatomical curve shape or curve of a curve or line containing the tooth tips of an average lower jaw of the human body. The curvature may be uniform or may be progressive with increasing distance from the holding device for the tool.
A further measure, to further improve the spatial situation, taking into account the restricted spatial conditions, consist in that the handpiece or its head is so configured that the side surface of the head towards the tool lies on an extension of the line of curvature.
Both above-mentioned measures contribute to the adaptation of the handpiece to the anatomical form of the lower jaw. In the first case, at least the outer side of the curved grip section follows the curve shape of a line containing the tooth tips of the lower jaw. By these means a maximum exploitable space for movement is available for the handpiece when working, which is bounded in the direction towards the lower jaw by its teeth. With this configuration in accordance with the invention the handpiece can exploit to the maximum extent the space available for movement. These advantages can be achieved not only when working lateral inner or outer surfaces, or lateral cavities, on the tooth, but also when working up occlusal cavities. Due to the spatially favourable shaping relatively long tools or working sections can also be used.
There are also medical handpieces which serve not for a material removing working of the human or animal body but for another kind of treatment, for example taking an image of the treatment site by means of light inlet arranged laterally in the forward end region of the handpiece, from which light inlet an image or light conductor extends rearwardly.
With such a handpiece the operating person does not need to carry out precision machining work with the handpiece, and needs only to exercise a holding force on the handpiece. In technical terminology such a handpiece is called a xe2x80x9cspecial purpose handpiecexe2x80x9d.
The object of the invention is to improve the spatial form of such a handpiece.
According to one embodiment of the invention, a forward longitudinal region of the handpiece is curved towards the side away from the light inlet.
The handpiece in accordance with this embodiment of the invention is, in its forward region, curved towards the side away from the inlet opening. By these means the handpiece can be ergonomically favourably manipulated at most of the treatment sites which arise when treating the human or animal body, whereby the operating hand gripping the handpiece can be moved in a readily manipulable manner. This is made possible by means of the curved form of the handpiece, with which the grip region of the rearward region of the handpiece rises up from the vicinity of the treatment site and thus a larger free space is available at least for the rearward region of the handpiece and for the operating hand.
The configuration in accordance with the invention is suited in particular for a dental-medical handpiece which is set up for the purpose of making images or video images of the teeth in the mouth of the patient. Such a handpiece in accordance with the invention is favourable not only with regard to the anatomical curvature shape or curve of a curve or line containing the tooth tips of an average lower jaw, but it is suitable also for the teeth of the upper jaw and for all conceivable treatment sites in the mouth, because the spatial form in accordance with the invention is favourable with regard to the position of the teeth and the mouth opening and therefore the handpiece can be favourably positioned with its light inlet in the mouth.
Preferred embodiments of the invention include elements which further improve the spatial form and contribute to readiness of manipulation.
Other further developing features of the invention make it possible to illuminate the treatment site, to adjust the focus of the handpiece, to simplify the construction of the handpiece, and to improve the security of gripping of the handpiece and also the appearance of the handpiece.